/** @file
  Boot service DXE ASL update library implementation.

  These functions in this file can be called during DXE and cannot be called during runtime
  or in SMM which should use a RT or SMM library.

  This library uses the ACPI Support protocol.

@copyright
  Copyright (c) 1999 - 2012 Intel Corporation. All rights reserved
  This software and associated documentation (if any) is furnished
  under a license and may only be used or copied in accordance
  with the terms of the license. Except as permitted by such
  license, no part of this software or documentation may be
  reproduced, stored in a retrieval system, or transmitted in any
  form or by any means without the express written consent of
  Intel Corporation.

  This file contains a 'Sample Driver' and is licensed as such
  under the terms of your license agreement with Intel or your
  vendor.  This file may be modified by the user, subject to
  the additional terms of the license agreement

**/
#include "Library/PchAslUpdateLib.h"

//
// Function implemenations
//
static EFI_ACPI_SUPPORT_PROTOCOL  *mAcpiSupport = NULL;
static EFI_ACPI_TABLE_PROTOCOL    *mAcpiTable   = NULL;

/**
  Initialize the ASL update library state.
  This must be called prior to invoking other library functions.

  @param[in] None

  @retval EFI_SUCCESS                  - The function completed successfully.
**/
EFI_STATUS
InitializePchAslUpdateLib (
  VOID
  )
{
  EFI_STATUS  Status;

  ///
  /// Locate ACPI tables
  ///
  Status = gBS->LocateProtocol (&gEfiAcpiSupportProtocolGuid, NULL, (VOID **) &mAcpiSupport);
  Status = gBS->LocateProtocol (&gEfiAcpiTableProtocolGuid, NULL, (VOID **) &mAcpiTable);
  return Status;
}

/**
  This procedure will update immediate value assigned to a Name

  @param[in] AslSignature      - The signature of Operation Region that we want to update.
  @param[in] Buffer            - source of data to be written over original aml
  @param[in] Length            - length of data to be overwritten

  @retval EFI_SUCCESS                  - The function completed successfully.
**/
EFI_STATUS
UpdateNameAslCode(
  IN     UINT32                        AslSignature,
  IN     VOID                          *Buffer,
  IN     UINTN                         Length
  )
{
  EFI_STATUS                  Status;
  EFI_ACPI_DESCRIPTION_HEADER *Table;
  EFI_ACPI_TABLE_VERSION      Version;
  UINT8                       *CurrPtr;
  UINT32                      *Signature;
  UINT8                       *DsdtPointer;
  UINT8                       Index;
  UINTN                       Handle;
  UINT8                       DataSize;

  ///
  /// Locate table with matching ID
  ///
  Index     = 0;

  do {
    Status = mAcpiSupport->GetAcpiTable (mAcpiSupport, Index, (VOID **) &Table, &Version, &Handle);
    if (Status == EFI_NOT_FOUND) {
      break;
    }

    ASSERT_EFI_ERROR (Status);
    Index++;
  } while (Table->Signature != EFI_ACPI_3_0_DIFFERENTIATED_SYSTEM_DESCRIPTION_TABLE_SIGNATURE);

  ///
  /// Point to the beginning of the DSDT table
  ///
  Index = 0;
  CurrPtr = (UINT8 *) Table;

  ///
  /// Loop through the ASL looking for values that we must fix up.
  ///
  for (DsdtPointer = CurrPtr; DsdtPointer <= (CurrPtr + ((EFI_ACPI_COMMON_HEADER *) CurrPtr)->Length); DsdtPointer++) {
    ///
    /// Get a pointer to compare for signature
    ///
    Signature = (UINT32 *) DsdtPointer;
    ///
    /// Check if this is the Device Object signature we are looking for
    ///
    if ((*Signature) == AslSignature) {
      ///
      /// Look for Name Encoding
      ///
      if(*(DsdtPointer-1) == AML_NAME_OP){
        ///
        /// Check if size of new and old data is the same
        ///
        DataSize = *(DsdtPointer+4);
        if ((Length == 1 && DataSize == 0xA) ||
            (Length == 2 && DataSize == 0xB) ||
            (Length == 4 && DataSize == 0xC) ) {
          CopyMem (DsdtPointer+5, Buffer, Length);
        }  else if (Length == 1 && ((*(UINT8*)Buffer) == 0 || (*(UINT8*)Buffer) == 1) && (DataSize == 0 || DataSize == 1)) {
          CopyMem (DsdtPointer+4, Buffer, Length);
        } else {
          FreePool (Table);
          return EFI_BAD_BUFFER_SIZE;
        }
        Status = mAcpiTable->UninstallAcpiTable (
                             mAcpiTable,
                             Handle
                             );
        Handle = 0;
        Status = mAcpiTable->InstallAcpiTable (
                             mAcpiTable,
                             Table,
                             Table->Length,
                             &Handle
                             );
        FreePool (Table);
        return Status;
      }
    }
  }
  return EFI_NOT_FOUND;
}

/**
  This procedure will update a Resource Descriptor Macro in
  Resrouce Template buffer list.

  @param[in] AslSignature      - The signature of Operation Region that we want to update.
  @param[in] BufferName        - signature of the Buffer inside OpRegion that we want to update
  @param[in] MacroAmlEncoding  - type of entry inside Buffer.
  @param[in] MacroEntryNumber  - number of entry of the above type
  @param[in] Offset            - offset (in bytes) inside entry where update will be performed
  @param[in] Buffer            - source of data to be written over original aml
  @param[in] Length            - length of data to be overwritten

  @retval EFI_SUCCESS                  - The function completed successfully.
**/
EFI_STATUS
UpdateResourceTemplateAslCode (
  IN     UINT32                        AslSignature,
  IN     UINT32                        BufferName,
  IN     UINT8                         MacroAmlEncoding,
  IN     UINT8                         MacroEntryNumber,
  IN     UINT8                         Offset,
  IN     VOID                          *Buffer,
  IN     UINTN                         Length
  )
{
  EFI_STATUS                  Status;
  EFI_ACPI_DESCRIPTION_HEADER *Table;
  EFI_ACPI_TABLE_VERSION      Version;
  UINT8                       *CurrPtr;
  UINT8                       *Operation;
  UINT32                      *Signature;
  UINT8                       *DsdtPointer;
  UINT8                       Index;
  UINTN                       Handle;
  UINT32                      AslLength;
  BOOLEAN                     EntryFound;

  ///
  /// Locate table with matching ID
  ///
  Index     = 0;
  AslLength = 0;
  EntryFound = FALSE;

  do {
    Status = mAcpiSupport->GetAcpiTable (mAcpiSupport, Index, (VOID **)&Table, &Version, &Handle);
    if (Status == EFI_NOT_FOUND) {
      break;
    }

    ASSERT_EFI_ERROR (Status);
    Index++;
  } while (Table->Signature != EFI_ACPI_3_0_DIFFERENTIATED_SYSTEM_DESCRIPTION_TABLE_SIGNATURE);

  ///
  /// Point to the beginning of the DSDT table
  ///
  Index = 0;
  CurrPtr = (UINT8 *) Table;

  ///
  /// Loop through the ASL looking for values that we must fix up.
  ///
  for (DsdtPointer = CurrPtr; DsdtPointer <= (CurrPtr + ((EFI_ACPI_COMMON_HEADER *) CurrPtr)->Length); DsdtPointer++) {
    ///
    /// Get a pointer to compare for signature
    ///
    Signature = (UINT32 *) DsdtPointer;

    ///
    /// Check if this is the Device Object signature we are looking for
    ///
    if ((*Signature) == AslSignature) {
      ///
      /// Read the Device Object block length
      ///
      if (*(UINT16 *)(DsdtPointer - 3) == AML_DEVICE_OP) {
        AslLength = *(DsdtPointer - 1);
      } else if (*(UINT16 *)(DsdtPointer - 4) == AML_DEVICE_OP) {
        AslLength = *(UINT16 *) (DsdtPointer - 2);
        AslLength = (AslLength & 0x0F) + ((AslLength & 0x0FF00) >> 4);
      } else if (*(UINT16 *)(DsdtPointer - 5) == AML_DEVICE_OP)  {
        AslLength = *(UINT32 *)(DsdtPointer - 3) & 0x00FFFFFFFF;
        AslLength = (AslLength & 0x0F) + ((AslLength & 0x0000FF00) >> 4) + ((AslLength & 0x00FF0000) >> 4);
      } else if (*(UINT16 *)(DsdtPointer - 6) == AML_DEVICE_OP)  {
        AslLength = *(UINT32 *)(DsdtPointer - 4);
        AslLength = (AslLength & 0x0F) + ((AslLength & 0x0000FF00) >> 4) + ((AslLength & 0x00FF0000) >> 4) + ((AslLength & 0xFF000000) >> 4);
      } else {
        continue; //Search for next instance
      }

      ///
      /// Conditional match.  Search AML Encoding in Device.
      ///
      for (Operation = DsdtPointer; Operation <= DsdtPointer + AslLength; Operation++) {
       ///
       /// Look for Name Encoding
       ///
       while(Operation <= DsdtPointer + AslLength) {
         if(*Operation == AML_NAME_OP){
          ///
          /// Found Name AML Encoding
          ///
          Operation++;
          if(*(UINT32 *)(Operation) == BufferName) {
           ///
           /// Found RBUF Resource Template object name
           ///
           break;
          }
         }
         Operation++;
       }

       if(Operation > DsdtPointer + AslLength ){
         continue; //Search for next instance
       }

       ///
       /// Now look for the Resource Template Object buffer opcode
       ///
       while((*Operation) != AML_BUFFER_OP) {
         Operation++;
         if(Operation > DsdtPointer + AslLength){
           FreePool (Table);
           return EFI_NOT_FOUND;
         }
       }

       ///
       /// Now look for the Macro to be updated until
       /// (1) it is found OR (2) reach end of resource template
       ///
       while(*(UINT16 *)(Operation) != AML_RESRC_TEMP_END_TAG) {
         if((*Operation == MacroAmlEncoding)) {
           ///
           /// We found a matching encoding however, the buffer list may have "n" number
           /// of same encoding entries. Let's narrow down to the "n"th entry.
           ///
           Index++;
           if(Index == MacroEntryNumber) {
             ///
             /// Get to the starting offset & end offset
             ///
             Operation += Offset;

             ///
             /// Fixup the value at the offset
             ///
             CopyMem ((VOID *) Operation, (VOID *) (Buffer), Length);

             ///
             /// Update the modified ACPI table
             ///
             Status = mAcpiTable->UninstallAcpiTable (
                                  mAcpiTable,
                                  Handle
                                  );
             Handle = 0;
             Status = mAcpiTable->InstallAcpiTable (
                                  mAcpiTable,
                                  Table,
                                  Table->Length,
                                  &Handle
                                  );
             FreePool (Table);
             return Status;
           }
         }
         Operation++;
       }

       if(Operation > DsdtPointer + AslLength) {
       FreePool (Table);
       return EFI_NOT_FOUND;
       }
      }
    }
  }

  return EFI_NOT_FOUND;
}

/**
  This function uses the ACPI support protocol to locate an ACPI table.
  It is really only useful for finding tables that only have a single instance,
  e.g. FADT, FACS, MADT, etc.  It is not good for locating SSDT, etc.

  @param[in] Signature           - Pointer to an ASCII string containing the OEM Table ID from the ACPI table header
  @param[in, out] Table          - Updated with a pointer to the table
  @param[in, out] Handle         - AcpiSupport protocol table handle for the table found
  @param[in, out] Version        - The version of the table desired

  @retval EFI_SUCCESS            - The function completed successfully.
**/
EFI_STATUS
LocateAcpiTableBySignature (
  IN      UINT32                        Signature,
  IN OUT  EFI_ACPI_DESCRIPTION_HEADER   **Table,
  IN OUT  UINTN                         *Handle,
  IN OUT  EFI_ACPI_TABLE_VERSION        *Version
  )
{
  EFI_STATUS              Status;
  INTN                    Index;
  EFI_ACPI_TABLE_VERSION  DesiredVersion;

  DesiredVersion = *Version;
  ///
  /// Locate table with matching ID
  ///
  Index = 0;
  do {
    Status = mAcpiSupport->GetAcpiTable (mAcpiSupport, Index, (VOID **)Table, Version, Handle);
    if (Status == EFI_NOT_FOUND) {
      break;
    }

    ASSERT_EFI_ERROR (Status);
    Index++;
  } while ((*Table)->Signature != Signature || !(*Version & DesiredVersion));

  ///
  /// If we found the table, there will be no error.
  ///
  return Status;
}

/**
  This function uses the ACPI support protocol to locate an ACPI SSDT table.

  @param[in] TableId           - Pointer to an ASCII string containing the OEM Table ID from the ACPI table header
  @param[in] TableIdSize       - Length of the TableId to match.  Table ID are 8 bytes long, this function
                      will consider it a match if the first TableIdSize bytes match
  @param[in, out] Table        - Updated with a pointer to the table
  @param[in, out] Handle       - AcpiSupport protocol table handle for the table found
  @param[in, out] Version      - See AcpiSupport protocol, GetAcpiTable function for use

  @retval EFI_SUCCESS       - The function completed successfully.
**/
EFI_STATUS
LocateAcpiTableByOemTableId (
  IN      UINT8                         *TableId,
  IN      UINT8                         TableIdSize,
  IN OUT  EFI_ACPI_DESCRIPTION_HEADER   **Table,
  IN OUT  UINTN                         *Handle,
  IN OUT  EFI_ACPI_TABLE_VERSION        *Version
  )
{
  EFI_STATUS  Status;
  INTN        Index;

  ///
  /// Locate table with matching ID
  ///
  Index = 0;
  do {
    Status = mAcpiSupport->GetAcpiTable (mAcpiSupport, Index, (VOID **)Table, Version, Handle);
    if (Status == EFI_NOT_FOUND) {
      break;
    }

    ASSERT_EFI_ERROR (Status);
    Index++;
  } while (CompareMem (&(*Table)->OemTableId, TableId, TableIdSize));

  ///
  /// If we found the table, there will be no error.
  ///
  return Status;
}

/**
  This function calculates and updates an UINT8 checksum.

  @param[in] Buffer          Pointer to buffer to checksum
  @param[in] Size            Number of bytes to checksum
  @param[in] ChecksumOffset  Offset to place the checksum result in

  @retval EFI_SUCCESS             The function completed successfully.
**/
EFI_STATUS
AcpiChecksum (
  IN VOID       *Buffer,
  IN UINTN      Size,
  IN UINTN      ChecksumOffset
  )
{
  UINT8 Sum;
  UINT8 *Ptr;

  Sum = 0;
  ///
  /// Initialize pointer
  ///
  Ptr = Buffer;

  ///
  /// set checksum to 0 first
  ///
  Ptr[ChecksumOffset] = 0;

  ///
  /// add all content of buffer
  ///
  while (Size--) {
    Sum = (UINT8) (Sum + (*Ptr++));
  }
  ///
  /// set checksum
  ///
  Ptr                 = Buffer;
  Ptr[ChecksumOffset] = (UINT8) (0xff - Sum + 1);

  return EFI_SUCCESS;
}
